Contaminant control filter with fill port

ABSTRACT

Filters, methods, and an apparatus for filling housings and both encapsulated porous and non-porous spaces with contaminant control media for placement in electronic enclosures, such as disk drive enclosures, are disclosed. In one embodiment, a filter assembly includes a housing comprising an internal cavity configured to receive contaminant control media, a fill port in communication with the internal cavity, and an opening in communication with the internal cavity, and filter media at least partially covering the opening; and contaminant control media occupying the internal cavity. Contaminant control media is deposited within the internal cavity via the fill port by means of creating a negative pressure within the internal cavity. The application of a partial vacuum facilitates movement of the contaminant control media into the internal cavity and minimizes the contamination of the filter, housing, and work space common to other loose fill filling methods. Other aspects and embodiments are provided herein.

PRIORITY

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/949,840, entitled “CONTAMINANT CONTROL FILTERWITH FILL PORT,” filed Jul. 13, 2007, the contents of which is hereinincorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a filter construction, an apparatus formaking the filter construction, and methods for making the filterconstruction.

BACKGROUND OF THE INVENTION

Contaminant control and recirculation filters have a variety of uses,including uses in electronic equipment. In the computer industry,contaminant control and recirculation filters are used within enclosuresfor electronic devices to protect the electronic components fromparticulate and gaseous contaminants. For example, disk drives ofteninclude contaminant control and recirculation filters within the diskdrive enclosure to protect the drive components and the disks fromcontaminants including water vapor, organic vapor, and out-gassing.Without such protection, these contaminants can lead to stiction,corrosion, and, in some instances, drive failure.

Frequently, contaminant control and recirculation filters have either aloose fill contaminant control (see U.S. Pat. No. 6,077,335) or acompression molded contaminant control of various configurations (see,e.g., U.S. Pat. No. 5,876,487 or U.S. Pat. No. 6,146,446). Each of theseconfigurations offers distinct advantages and disadvantages. A loosefill contaminant control media is generally less expensive than one thatis compression molded. However, loose fill contaminant control media isdifficult to manipulate due to its granular or beaded nature, and cancause contamination of the clean room, the filter housing, and thesurfaces that require welding after deposition of the loose fillcontaminant control media. Compression molded contaminant controls aregenerally easier to handle and are cleaner to use in a clean roomenvironment. However, they are more expensive, require tooling that addsto cost and labor time, and are much less efficient in contaminantadsorption. Clearly, a new filter design which overcomes thesechallenges would be desirable.

SUMMARY OF THE INVENTION

Generally, the present invention relates to adsorbent or recirculationfilters for placement in an electronic enclosure, such as a hard diskdrive, methods of filling these filters with a contaminant controlmedia, and an apparatus capable of accomplishing the filling.

In an embodiment, the invention includes a method for filling a filterassembly with a contaminant control media comprising the steps of:providing a housing containing an internal cavity, at least one fillport formed in the housing and in communication with the internal cavityof the housing, and an opening with filter media at least partiallycovering the opening; providing contaminant control media; creating anegative pressure with the internal cavity by drawing a partial vacuumwithin the cavity; and drawing the contaminant control media into theinternal cavity under partial vacuum. In addition to drawing in theadsorbent, the partial vacuum also prevents dust created during handlingthe adsorbent or filling the cavity from escaping and contaminating themanufacturing room. The filter media can comprise ePTFE, the contaminantcontrol media can comprise an adsorbent material and neutralizationmaterial, and the filter assembly can be configured for insertion intoan electronic enclosure.

In an embodiment, the invention includes a method for filling a porousfilter assembly with a contaminant control media, comprising the stepsof: providing a porous container at least partially formed of filtermedia; providing the contaminant control media; drawing a partial vacuumacross the porous container; and drawing the contaminant control mediainto the porous container under partial vacuum. The filter media cancomprise ePTFE and the contaminant control media can comprise anadsorbent material and neutralization material. The porous container cancomprise a filter bag or a molded housing and the filter assembly can beconfigured for insertion into an electronic enclosure.

In an embodiment, the invention includes a filter assembly for use in anelectronic enclosure including a housing comprising: an internal cavitywithin the housing, the internal cavity configured to receivecontaminant control media, at least one fill port in communication withthe internal cavity, an opening in communication with the cavity, andfilter media at least partially covering the opening. Contaminantcontrol media occupies the internal cavity. The filter media cancomprise ePTFE and the contaminant control media can comprise anadsorbent material and neutralization material. The filter assembly canbe configured for insertion into an electronic enclosure.

In an embodiment, the invention includes a delivery apparatuscomprising: a holding unit configured to retain contaminant controlmedia; an assembly configured to deposit contaminant control media intoan encapsulated space; and a device capable of creating a negativepressure within the encapsulated space to facilitate movement of thecontaminant control media into the encapsulated space and to prevent theescape of any dust (aerosol) created during the filling.

This summary of the present invention is merely an overview of some ofthe teachings of the present application and is not intended to describeeach disclosed embodiment or every implementation of the presentinvention. Further embodiments will be found in the figures, detaileddescription, and claims. The scope of the present invention should bedetermined by the appended claims and their legal equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in connection with thefollowing drawings, in which:

FIG. 1 is a perspective view of one embodiment of a filter assembly,according to the invention.

FIG. 2 is a top plan view of the filter assembly of FIG. 1.

FIG. 3 is a bottom plan view of the filter assembly of FIG. 1.

FIG. 4 is a side elevational view of the filter assembly of FIG. 1.

FIG. 5 is a schematic cross sectional view of the filter assembly alongline A-A′ of FIG. 2.

FIG. 6 is an inverted cross sectional view of the housing for a filterassembly, prior to being filled with contaminant control media.

FIG. 7 is a schematic diagram of an apparatus for loading contaminantcontrol media into a housing for a filter, the apparatus including asource for contaminant control media and a coupling device for applyinga vacuum to a surface of the housing.

FIG. 8 shows the apparatus for loading contaminant control media of FIG.7 along with the housing for a filter assembly of FIG. 6, wherein thehousing is mounted on the apparatus for loading but before loading thehousing with contaminant control media.

FIG. 9 shows the apparatus for loading contaminant control media of FIG.7 along with the housing for a filter assembly of FIG. 6, wherein thehousing is partially filled with contaminant control media.

FIG. 10 shows the apparatus for loading contaminant control media ofFIG. 7 along with the housing for a filter assembly of FIG. 6, whereinthe housing is filled with contaminant control media.

FIG. 11 shows the housing for a filter assembly of FIGS. 6 to 10, afterthe housing has been removed from the apparatus for loading contaminantcontrol media.

FIG. 12A shows the housing for a filter assembly of FIGS. 6 to 11, aftera mounting label with release liner has been added and the fill hole inthe housing has been closed.

FIG. 12B shows a bottom plan view of the filter assembly of FIG. 12A.

FIG. 13 shows the housing for a filter assembly of FIGS. 6-12, whereinthe filter assembly has been mounted within an electronic enclosure.

FIG. 14A shows an alternative filter assembly of the invention, whereinthe fill hole is configured for use as a breather hole.

FIG. 14B shows a bottom plan view of the filter assembly of FIG. 14A.

FIG. 15A shows an alternative filter assembly, wherein the fill hole issealed completely and the filter does not include a breather hole.

FIG. 15B shows a bottom plan view of the filter assembly of FIG. 15A.

FIG. 16A shows an alternative filter assembly of the invention, whereinthe fill hole is positioned along the side of the filter assembly.

FIG. 16B shows a bottom plan view of the filter assembly of FIG. 16A.

FIG. 17A shows an alternative filter assembly of the invention, whereinfilter media is placed on two sides of the filter assembly.

FIG. 17B shows a top plan view of the filter assembly of FIG. 17A.

FIG. 18A shows an alternative filter assembly of the invention, whereinthe filter media and fill port are positioned on the same surface of thefilter assembly.

FIG. 18B shows a top plan view of the filter assembly of FIG. 18A.

FIG. 19A shows an alternative filter assembly of the invention, whereinthe filter media and fill port are positioned on the same surface of thefilter assembly, further comprising a scrim over the breather port.

FIG. 19B shows a side cross sectional view of a filter assemblyincluding a diffusion channel.

FIG. 19C shows a top plan view of the filter assembly of FIG. 19A.

FIG. 20 shows a top plan view of an alternative filter assembly.

While the invention is susceptible to various modifications andalternative forms, specifics thereof have been shown by way of exampleand drawings, and will be described in detail. It should be understood,however, that the invention is not limited to the particular embodimentsdescribed. On the contrary, the intention is to cover modifications,equivalents, and alternatives falling within the spirit and scope of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is applicable to filters and methods of making andusing filters to filter a fluid, such as, for example, air or othergases. The filter construction can reduce contaminants within anelectronic enclosure, such as a disk drive housing, by a variety ofprocesses. One process for reducing, removing, or preventingcontamination within the disk drive housing is to reduce or removecontaminants entering the disk drive housing from regions outside of thedisk drive housing (or other device). The breather embodiment of thefilter construction is constructed for this purpose. A second processfor reducing, removing or preventing contamination from within the diskdrive housing is to reduce or remove contaminants present in the diskdrive housing atmosphere. The recirculation embodiment of the filterconstruction, can be constructed for this purpose. In addition, anadsorbent assembly can be used to remove contaminants from the inside ofa drive. The adsorbent assembly contains contaminant control media, andis placed within the electronic enclosure, but does not have arecirculation function and does not communicate by a breather hole withthe exterior of the enclosure. However, the adsorbent assembly stillremoves contaminants from the drive interior.

In one embodiment, the invention includes a method for filling a filterassembly with a contaminant control media under partial vacuum in afashion such that the filter assembly is filled with minimal externalcontamination. In such embodiments the method comprises the steps ofproviding a housing containing an internal cavity, at least one fillport in communication with the internal cavity, and an opening withfilter media at least partially covering said opening. An air flowthrough the fill hole is created by applying a partial vacuum to theoutside of the porous media and this air flow helps draw in thecontaminant control media and prevents dust from escaping through thefill hole. The filter media can comprise ePTFE, the contaminant controlmedia can comprise an adsorbent material and neutralization material,and the filter assembly can be configured for insertion into anelectronic enclosure.

The filter construction generally includes a particulate or solidremoval element and a contaminant control element. Examples ofparticulate or solid removal elements include, but are not limited to,filter materials such as polymers, non-woven materials, fibers, paper,and the like. Examples of contaminant control elements include, but arenot limited to, adsorbent material, neutralization material, and thelike. Additionally or alternatively, a tortuous or extended path, suchas a diffusion channel, can be used to restrict contaminant entry intothe electronic enclosure when the filter construction is used as abreather filter.

Various aspects of the invention will now be discussed in reference tothe figures. Referring to FIGS. 1 and 2, one embodiment of the inventionincludes a filter assembly 10 comprising a housing 40 having a top 20,base 30, sidewall 24, and filter media 50 secured to the top 20.Although FIGS. 1 and 2 depict the housing 40 as generally cylindrical inshape, it will be appreciated that various embodiments can includemultiple sidewalls defining various shape and sizes of the filterassembly 10. For example, the housing 40 can be rectangular, oval,square, circular, triangular, or generally any other shape desired.

In many applications the housing will be constructed such that it iscustomized for a specific electronic enclosure, so that it fits withinan appropriate portion of the enclosure without interfering with otherequipment within the enclosure. For example, when placed within a diskdrive assembly, the filter assembly 10 having housing 40 must avoidcontact with the spinning disks and read/write head of the disk drive,while also allowing adequate clearance with these moving parts to avoidcreating undesirable air turbulence. One of the benefits of the presentinvention is that it allows a wide variety of shapes and sizes of filterassemblies 10 to be manufactured with minimal retooling for differentassembly configurations.

Although FIGS. 1 and 2 depict the filter media 50 as generally acircular shape covering the majority of the top 20, it will beappreciated that the filter media 50 can be of any shape and can coverdifferent sizes, areas, and dimensions (including one or moresidewall(s) and the base 30) of the filter assembly 10. It will beappreciated that the filter media 50 can be secured with a variety ofmethods including, but not limited to, mold casting, welding, adhesives,mechanical connections, and the like.

FIG. 3 portrays a bottom plan view of the embodiment of the filterassembly shown in FIGS. 1 and 2. The base 30 of the filter assembly 10defines a fill port 60 (indicated by phantom circle). The fill port 60is used to fill the internal cavity of the housing 40 with contaminantcontrol media 90 (shown in FIG. 5). After the internal cavity of thehousing 40 is filled, the fill port 60 can be sealed. In one embodimentof the invention, the fill port 60 is sealed with an adhesive mountinglabel 70.

The mounting label 70, serves a dual purpose in the embodiment of theinvention shown in FIGS. 1, 2, 3, 4, and 5. The mounting label 70 bothseals the fill port 60 and holds the filter assembly 10 in theelectronic enclosure. The mounting label 70 can be, for example, adouble-sided adhesive film that includes an adhesive carrier withadhesive disposed on both sides. In such embodiments the mounting label70 can both seal the fill port 60 during manufacture and later securethe filter assembly 10 to a mounting surface, such as the interior wallof a hard disk drive. The adhesive carrier is typically a polymer film,such as, for example, a polyethylene, polypropylene, polyester,polycarbonate, polyurethane, or polyvinyl chloride film. Suitableadhesives include, but are not limited to, epoxies, resins,pressure-sensitive adhesives, hot-melt adhesives, solvent-basedadhesives, emulsion-based adhesives, and contact adhesives. One exampleof a suitable adhesive is 3M 502FL adhesive from 3M Co. (St. Paul,Minn.).

It will be appreciated that the fill port 60 can also be sealed with avariety of other methods including, but not limited to, snug fit plugs,filter media, ultrasonic welding, and the like. If a mounting label 70is not used, an additional adhesive media may be necessary. Or, in thealternative, the filter assembly 10 can be held in the electronicenclosure by mechanical techniques, including, but not limited to,clips, frames, welding, or the like. Although FIG. 3 depicts the fillport 60 as generally a circular shape, it will be appreciated that thefill port 60 can be any shape.

Referring again to FIG. 3, in the depicted embodiment of the inventionthe base 30 of the filter assembly 10 defines a breather port 80. Thebreather port 80 permits the flow of fluid from the outside of theelectronic enclosure into the electronic enclosure. The breather port 80allows the flow of air to come into contact with the contaminant controlmedia 90 disposed within the internal cavity of the filter housing 40prior to the flow of air exiting the filter assembly 10. Although FIG. 3depicts the breather port 80 as generally a circular shape, it will beappreciated that the breather port 80 can be of any shape. Also,although not depicted herein, the breather port can be connected to adiffusion channel, molded into the base 70, formed by one or more thinfilms, or formed within the surface on which the filter assembly 10 isultimately mounted (such as the interior wall of a disk drive).

FIG. 4 portrays a schematic side view of the embodiment of the inventionshown in FIGS. 1, 2, and 3. The mounting label 70 can be seen present onthe base 30 of one embodiment of the invention.

FIG. 5 portrays a cross-sectional view of the embodiment of theinvention shown in FIG. 1 to 4, with the cross section taken along lineA-A′ of FIG. 2. The filter media 50 is secured to the top 20. The base30 of the housing 40 defines the fill port 60 that has been sealed bythe mounting label 70, and the base 30 of the housing 40 in conjunctionwith the mounting label 70 helps further define the breather port 80.The housing 40 also defines the internal cavity within which thecontaminant control media 90 is deposited via the fill port 60. It willbe appreciated that the contaminant control media 90 is of sufficientsize, shape, or composition that it is unable to escape through thebreather port 60 in the embodiment depicted. Thus, for example, if thebreather port is 2 mm in diameter, then it would be desirable to usecontaminant control media that is 3 mm in diameter (or at least greaterthan 2 mm in diameter). In the alternative a scrim or other material canbe placed over the interior or exterior of the breather port to preventescape of the contaminant control media. Further detailed discussion ofthe contaminant control media can be found below.

FIG. 6 portrays an inverted cross sectional view of one embodiment ofthe invention, prior to filling the housing with contaminant controlmedia. The filter assembly 110 is defined by a housing 140 having a top120, base 130, sidewall 124, and filter media 150 secured to the top 20.The base 130 of the housing 140 defines a fill port 160 and a breatherport 180.

FIGS. 7-10 portray a schematic diagram, and mechanism of operation, ofone embodiment of a filling apparatus capable of loading contaminantcontrol media into the housing of a filter assembly. The fillingapparatus 191 includes contaminant control media 190 placed within aloading unit 192. The filling apparatus 191 further comprises a loadingstation 194 where the housing 140 for the filter assembly 110 will beplaced. The loading station 194 will also be capable of drawing a vacuumacross a surface of the housing 140 containing filter media 150 andtherefore will further comprise a vacuum generating apparatus. Theloading station 194 will further contain a coupling device 196 forattaching the housing 140 to the loading station 194 and forfacilitating the creation of a seal sufficient to draw a partial vacuumacross a surface of the housing 140 containing filter media 150.

FIG. 8 portrays the filling apparatus 191 where the loading station 194is occupied by a housing 140 for the filter assembly 110 found in FIG.6. The loading unit 192 is engaged with the housing 140 at the fill port160 on the base 130 and is capable of depositing the contaminant controlmedia 190 into the internal cavity of the housing 140. To facilitatedelivery of the contaminant control media 190, a partial vacuum will bedrawn across the filter media 150; the vacuum generating apparatus beingcoupled to the loading station 194 and the seal for drawing the vacuumacross filter media 150 being facilitated by the coupling device 196located on the loading station 194. It will be appreciated that in thisembodiment the breather port 180 must be sealed in order to generate thepartial vacuum and in this embodiment, the loading unit 192 is capableof sealing the breather port 180. It will be appreciated that thebreather port 180 can also be sealed with any other temporary mechanism,for example, a removable adhesive tape or label.

FIG. 9 portrays the loading apparatus loading contaminant control mediainto the internal cavity of the filter assembly from FIG. 6; the taskbeing partially completed. The application of a partial vacuumfacilitates movement of the contaminant control media 190 from theloading unit 192, through the filler port 160 on the base 130 of thehousing 140, and into the internal cavity of the housing 140 of thefilter assembly 110. A seal sufficient to create a partial vacuum iscreated by 1) temporarily sealing the breather port 180 and 2) thecoupling device 196 of loading unit 194 creating a seal across thefilter media 150 of the housing 140.

FIG. 10 portrays the loading apparatus loading contaminant control mediainto the internal cavity of the filter assembly; the task beingcompleted. The internal cavity of the housing 140 of the filter assembly110 can be completely and efficiently filled with contaminant controlmedia 190 because of the application of a partial vacuum across thefilter media 150 of the housing 140 and the temporary sealing of thebreather port 180.

It will be appreciated that FIGS. 7-10 only represent a single,simplified schematic of the filling apparatus 191 and that variousembodiments of the filling apparatus will exist to fill variousembodiments of the filter assembly. The general purpose of the fillingapparatus is to provide a mechanism to fill the internal cavity of afilter housing with contaminant control media. The contaminant controlmedia is drawn into the internal cavity of the filter housing by drawinga partial vacuum on at least a portion of one surface of the filterhousing at least partially covered with secured filter media.

FIG. 11 portrays the housing for the filter assembly of FIGS. 6 to 10 inan inverted position, after the filter assembly has been removed fromthe loading apparatus. The internal cavity of the housing 140 of filterassembly 110 is completely occupied by the contaminant control media 190that was loaded via the fill port 160. It will be appreciated that inthis embodiment the contaminant control media 190 is of sufficient size,shape, or composition that is unable to escape the internal cavity ofthe housing 140 of the filter assembly 110 via the breather port 180.

FIG. 12A portrays the filter assembly 110 in an upright position after amounting label has been attached to the base 130 of the housing 140. Themounting label 170 closes the fill port 160; thereby preventing thecontaminant control media 190 from escaping the internal cavity of thehousing 140. The mounting label 170 further defines the breather port180 located on the base 130 of the housing 140 of the filter assembly110. The mounting label 170 can be, for example, a double-sided adhesivefilm that includes an adhesive carrier with adhesive disposed on bothsides. One adhesive surface can bind to the base 130 of the filterassembly 110 and the second adhesive surface can be protected by arelease liner 174. The release liner 174 can be removed, therebyexposing a second adhesive surface that can be used to secure the filterassembly 110 to an internal surface of an electronic enclosure.

FIG. 12B portrays a bottom plan view of the filter assembly of FIG. 12A.The base 130 of the housing 140 of the filter assembly 110 defines thebreather port 180 and the fill port 160 (indicated by phantom circle).The base 130 is partially covered by a mounting label 170 that can be,for example, a double-sided adhesive film that includes an adhesivecarrier with adhesive disposed on both sides. The mounting label 170seals the fill port 160, while allowing the breather port 180 tomaintain fluid communication with the external environment. The mountinglabel 170 further comprises a release liner 174 that protects the secondadhesive surface from environmental exposure. The release liner 174 canbe removed, thereby exposing the second adhesive surface that can thenbe use to secure the filter assembly 110 to an internal surface of anelectronic enclosure. It will be appreciated that although the fill port160 and breather port 180 are depicted as generally circular, they canbe of any shape.

FIG. 13 portrays the filter assembly of FIGS. 6-12 where the filterassembly is mounted within an electronic enclosure. The filter assembly110 is secured within the electronic enclosure 105 via the mountinglabel 170. The release liner 174 of FIG. 12B had been removed, exposingthe second adhesive surface, and said surface is used to secure thefilter assembly 110 to the electronic enclosure 105. The filter assembly110 is in fluid communication with the external environment via thebreather port 180. It will be appreciated that that contaminant controlmedia 190 is of a sufficient size, shape, or composition that it isunable to escape via the breather port 180. In this embodiment of theinvention, the filter assembly 110 serves as an adsorbent breatherfilter.

FIG. 14A portrays a schematic cross sectional view of another embodimentof the invention where the fill port is configured for use as thebreather port. Thus, the fill port is initially used to fill the housingwith contaminant control media, after which the port's diameter istypically reduced to prevent escape of the contaminant control media,but to still allow the fill port to function as a breather port. Inalternative to reducing the diameter of the fill port, it is possible toplace a porous media or scrim over the fill port to retain contaminantcontrol media. The internal cavity of the housing 240 of the filterassembly 210 contains the contaminant control media 290. The contaminantcontrol media 290 is loaded into the internal cavity of the housing 240via the fill port 260 found on the base 230 of the filter assembly 210.The housing 240 further comprises a top 220 to which filter media 250 issecured. In this embodiment of the invention, a mounting label 270 isaffixed to the base 230 to decrease the diameter of the fill port 260.

The diameter of the fill port 260 should be decreased so that 1) thefill port 260 can be configured into the breather port and 2) thecontaminant control media 290 does not escape through the fill port 260.It will be appreciated that that contaminant control media 290 is of asufficient size, shape, or composition, that it is unable to escape viathe breather port. The mounting label 270 can be, for example, adouble-sided adhesive film that includes an adhesive carrier withadhesive disposed on both sides. The mounting label 270 will furtherallow the filter assembly 210 to be secured within an electronicenclosure.

FIG. 14B portrays a bottom plan view of the filter assembly of FIG. 14A.The base 230 of the filter assembly 210 defines a fill port 260(indicated by phantom circle). Initially, the fill port 260 is used tofill the internal cavity of the housing 240 with contaminant controlmedia 290; later the fill port 260 is configured into the breather port(indicated by the intact circle within the phantom circle that definedthe fill port 260) by the addition of the mounting label 270. Themounting label 270 sufficiently decreases the size of the fill port 260so that the contaminant control media 290 cannot escape. Additionally,the mounting label 270 will allow the filter assembly 210 to be securedwithin an electronic enclosure. It will be appreciated that although thefill port 260 and breather port are depicted as generally circular, theycan be of any shape. In this embodiment of the invention, the filterassembly 210 serves as an adsorbent breather filter.

FIG. 15A portrays another embodiment of the invention where the fillport is completely sealed and there is no breather port. The internalcavity of the housing 340 of the filter assembly 310 contains thecontaminant control media 390. The contaminant control media 390 wasloaded into the internal cavity of the housing 340 via the fill port 360found on the base 330 of the filter assembly 310. The housing 340further comprises a top 320 to which filter media 350 is secured. Thebase 330 is partially covered by a mounting label 370 that can be, forexample, a double-sided adhesive film that includes an adhesive carrierwith adhesive disposed on both sides. The mounting label 370 seals thefill port 360 after the contaminant control media 390 has been loadedinto the internal cavity of the housing 340. The mounting label 370 canfurther comprise a release liner that protects the second adhesivesurface from environmental exposure. The release liner can be removed,thereby exposing the second adhesive surface, and the entire filterassembly 310 can be secured to an internal surface of an electronicenclosure. The assembly of FIG. 15A is particularly useful as anadsorbent assembly within an electronic enclosure.

FIG. 15B portrays a bottom plan view of the filter assembly of FIG. 15A.The base 330 of the filter assembly 310 defines a fill port 360(indicated by phantom circle). This fill port 360 is used to fill theinternal cavity of the housing 340 with contaminant control media 390.The mounting label 370 is affixed to the base 330 of the filter assembly310 to seal the fill port 360. This embodiment of the invention lacks abreather port and therefore can be used as an adsorbent filter.

FIG. 16A portrays another embodiment of the filter assembly where thefill port is positioned on a side wall of the filter assembly. Theinternal cavity of the housing 440 of the filter assembly 410 containsthe contaminant control media 490. The contaminant control media 490 wasloaded into the internal cavity of the housing 440 via the fill port 460found on the sidewall 424 of the filter assembly 410. The housing 440further comprises a top 420 to which filter media 450 is secured.

The base 430 is partially covered by a mounting label 470 that can be,for example, a double-sided adhesive film that includes an adhesivecarrier with adhesive disposed on both sides. The mounting label 470 isused to secure the filter assembly 410 to a mounting surface, such asthe interior surface of an electronic enclosure. The fill port 460 canbe sealed with an adhesive label 464 and can be, for example, a singlesided adhesive film that includes an adhesive carrier with adhesivedisposed on a single side. In an alternative embodiment, the fill port460 can be designed so that it can be sealed with tight fitting plug.

FIG. 16B portrays a bottom plan view of the filter assembly of FIG. 16A.To the base 430 of the housing 440 of the filter assembly 410 is affixeda mounting label 470. The mounting label 470 can further comprise arelease liner that protects the second adhesive surface fromenvironmental exposure. The release liner can be removed, therebyexposing the second adhesive surface, and the entire filter assembly 410can be secured to an internal surface of an electronic enclosure. On thesidewall 424 of the housing 440 is the fill port 460 of FIG. 16A thatcan be sealed with an adhesive label 464. It will be appreciated thatalthough the filter assembly 410 in this embodiment is cubical in shape,the filter assembly 410 can be of any shape. This embodiment of theinvention lacks a breather port and therefore can be used as anadsorbent filter.

FIG. 17A portrays another embodiment of the invention where filter mediais secured to two dimensions of the filter assembly. The internal cavityof the housing 540 of the filter assembly 510 contains the contaminantcontrol media 590. The contaminant control media 590 was loaded into theinternal cavity of the housing 540 via the fill port 560 found on thesidewall 524 of the filter assembly 510. The housing 540 furthercomprises a top 520 and base 530 to which filter media 550 is secured.It will be appreciated that the filter media 550 can be secured with avariety of methods including, but not limited to, mold casting, welding,adhesives, mechanical connections, and the like. It will be furtherappreciated that the filter assembly 510 can be held in the electronicenclosure by mechanical techniques, including, but not limited to,clips, frames, welding, or the like. The fill port 560 can be sealedwith an adhesive label 564 that can be, for example, a single sidedadhesive film that includes an adhesive carrier with adhesive disposedon a single side. In an alternative embodiment, the fill port 560 can bedesigned so that it can be sealed with tight fitting plug.

FIG. 17B portrays a top plan view of the filter assembly of FIG. 17A.The top 520 of the housing 540 of the filter assembly 510 partiallycomprises secured filter media 550. The fill port 560 of FIG. 17Alocated on sidewall 424 is sealed with an adhesive label 464. It will beappreciated that although the filter assembly 510 in this embodiment iscubical in shape, the filter assembly 410 can be of any shape. Thisembodiment of the invention lacks a breather port and therefore can beused as an adsorbent filter.

FIG. 18A portrays another embodiment of the invention where the securedfilter media and the fill port are located on the same surface of thefilter assembly. The internal cavity of the housing 640 of the filterassembly 610 contains the contaminant control media 690. The contaminantcontrol media 690 was loaded into the internal cavity of the housing 640via the fill port 660 found on the same surface upon which the securedfilter media 650 is positioned. The fill port 660, in FIG. 18A, is shown“unsealed”. A weld horn, in conjunction with ultrasonic welding, can beused on the protrusions 664 of the fill port 660 to seal the filterassembly 610. The housing 640 further comprises a top 620 to whichfilter media 650 is secured and a base 630 that defines a breather port680. The breather port is further defined by a mounting label 670. Thebase 630 is partially covered by a mounting label 670 that can be, forexample, a double-sided adhesive film that includes an adhesive carrierwith adhesive disposed on both sides. The mounting label 670 is used tosecure the filter assembly 610 to a mounting surface, such as theinterior surface of an electronic enclosure.

FIG. 18B portrays a top plan view of the filter assembly of FIG. 18A.The top 620 of the housing 640 of the filter assembly 610 partiallycomprises secured filter media 650. The fill port 660 of FIG. 18Alocated on the top 620 and has been sealed with a weld horn inconjunction with ultrasonic welding. It will be appreciated thatalthough the filter assembly 610 in this embodiment is generally oval inshape, the filter assembly 610 can be of any shape. This embodiment ofthe invention can be used as a breather adsorbent filter.

FIG. 19A portrays another embodiment of the invention where the securedfilter media and the fill port are located on the same surface of thefilter assembly and a scrim that covers the breather port is locatedwithin the internal cavity of the housing. The internal cavity of thehousing 740 of the filter assembly 710 contains the contaminant controlmedia 790. The contaminant control media 790 was loaded into theinternal cavity of the housing 740 via the fill port 760 found on thesame surface upon which the secured filter media 750 is positioned. Thefill port 760 can be sealed with an adhesive label 764 that can be, forexample, a single sided adhesive film that includes an adhesive carrierwith adhesive disposed on a single side.

In an alternative embodiment, the fill port 760 can be designed so thatit can be sealed with tight fitting plug. The housing 740 furthercomprises a top 720 to which filter media 750 is secured and a base 730that defines a breather port 780. The breather port is further definedby a mounting label 770. The base 730 is partially covered by a mountinglabel 770 that can be, for example, a double-sided adhesive film thatincludes an adhesive carrier with adhesive disposed on both sides. Themounting label 770 is used to secure the filter assembly 710 to amounting surface, such as the interior surface of an electronicenclosure. Within the housing 740, adjacent to the base 730, and abovethe breather port 780, is placed a scrim 752. This scrim 752 can becomposed of similar material as the filter media 750 and the scrim 752can function to filter the incoming fluid or prevent the contaminantcontrol media 790 from escaping through the breather port 780.

In the embodiment portrayed in FIG. 19B, the scrim 752 defines adiffusion channel 756 and a breather port 780. The diffusion channel 756provides a tortuous or extended path that can be used to restrictcontaminant entry into the electronic enclosure. The diffusion channel756 can be formed as a straight or curved path. Alternatively, thediffusion channel 756 may be formed to have a more complex path, such asa winding path or a spiral path. For example, the diffusion channel canbe configured as an inwardly spiraling channel, an outwardly spiralingchannel, or as a maze-like configuration. The diffusion channel 756 can,in some embodiments, have two or more branches.

Examples of diffusion channels for use with computer disk drive systemsare described in U.S. Pat. No. 4,863,499, incorporated herein byreference. Other examples of a diffusion channels defined by diffusionchannel layer of film are described in U.S. Pat. No. 5,997,614,incorporated herein by reference. Fluid enters the breather port 780,travels through diffusion channel 756, and then enters the internalcavity of the filter housing 740. Fluid can also travel through thispathway in the reverse direction depending on relative air pressure.

Referring again to FIG. 19B, the base 730 includes a scrim 752. Thescrim 752 defines the diffusion channel 756. The boundary layer 754 canbe formed using a polymer or metallic film or a plastic layer. Theboundary layer 754 is typically nonporous and has a low permeability tothe fluid to be filtered, particularly, at the fluid pressures expectedfor operation of the filter assembly 710. Examples of suitable polymerfilms for use in the boundary layer 754 include polyester (e.g., Mylar),polyethylene, polypropylene, nylon, polycarbonate, polyvinyl chloride,and polyvinyl acetate films. Preferably, the polymer films haverelatively low or no out-gassing. Suitable metallic films for use in thediffusion boundary layer 754 include films formed using metals, such as,for example, copper and aluminum, and alloys, such as, for example,stainless steel. Preferred metal films do not significantly corrode orform reaction products (e.g., rust) that can be dislodged from the filmunder the expected operating conditions of the filter. In someembodiments, the metallic film may be deposited or otherwise formed on abase material, such as, for example, a polymer film.

FIG. 19C portrays a top plan view of the filter assemblies of FIGS. 19Aand 19B. The top 720 of the housing 740 of the filter assembly 710partially comprises secured filter media 750. The fill port 760 can besealed with an adhesive label 764 that can be, for example, a singlesided adhesive film that includes an adhesive carrier with adhesivedisposed on a single side. In an alternative embodiment, the fill port760 can be designed so that it can be sealed with tight fitting plug. Itwill be appreciated that although the filter assembly 710 in thisembodiment is generally oval in shape, the filter assembly 710 can be ofany shape. This embodiment of the invention can be used as a breatheradsorbent filter

FIG. 20 portrays a top plan view of another embodiment of the invention.Arrows show fluid entering the filter assembly 810 through one securedfilter media 850 and exiting the filter assembly 810 housing 840 througha second secured filter media 850. The housing 840 further defines a top820 upon which a fill port 860 is located; the fill port 860 being usedto deposit contaminant control media within the internal cavity of thehousing 840. In alternative embodiments, the fill port 860 can belocated on the base or the sidewall of the housing 840. The fill port860 can be sealed with an adhesive label 864 that can be, for example, asingle sided adhesive film that includes an adhesive carrier withadhesive disposed on a single side. In an alternative embodiment, thefill port 860 can be designed so that it can be sealed with tightfitting plug. In this embodiment, the invention can be used as arecirculation filter.

In an alternative embodiment of FIG. 20, the invention further comprisesa base that can define a breather port that is in fluid communicationwith both the internal cavity of the housing of the filter assembly andthe external environment. In this embodiment, the invention can be usedas a breather recirculation filter. In an alternative embodiment of FIG.20, the invention further comprises a breather port and diffusionchannel. In this embodiment, the invention can be used as a breatherrecirculation filter.

Contaminant Control Material

Typically, the contaminant control media is disposed within the internalcavity of the housing or within a porous or non-porous encapsulatedspace. The contaminant material can be any suitable material for theremoval, reduction, entrapment, immobilization, adsorption, absorption,and neutralization of contaminants.

The contaminant control media is typically provided for the removal ofchemical contaminants. The contaminant control media can removecontaminants from the air entering the enclosure atmosphere or alreadypresent within the enclosure atmosphere by adsorption, neutralization,or immobilization. As used throughout this application, the terms“adsorb,” “adsorption,” “adsorbent” and the like, are intended to alsoinclude the mechanism of absorption. Typically, the contaminant controlmedia is selected to be stable and adsorb or neutralize contaminantswithin normal disk drive operating temperatures, for example, within arange of about −40° C. to 100° C.

The contaminant control media adsorbs or neutralizes one or more typesof contaminants, including, for example, water, water vapor, acid gas,and volatile organic compounds. The contaminant control media caninclude adsorbent material (physisorbent or chemisorbent material), suchas, for example, a desiccant (i.e., a material that adsorbs or absorbswater or water vapor) or a material that adsorbs or absorbs volatileorganic compounds, acid gas, or both. Suitable adsorbent materialsinclude, for example, activated carbon, activated alumina, molecularsieves, silica gels, potassium permanganate, calcium carbonate,potassium carbonate, sodium carbonate, calcium sulfate, or mixturesthereof. Carbon is suitable for most implementations, and carbonsuitable for use with the present invention is disclosed in U.S. Pat.No. 6,077,335, incorporated herein by reference in its entirety.

Additionally, contaminant control media can include neutralizationmaterial. Neutralization material can include acid or base impregnatedsubstances that can effectively neutralize the gaseous contaminantsfound within the housing or electronic enclosure. Neutralizationmaterial can also include enzyme or catalyst impregnated substances thatincrease the rate of degradation of the gaseous contaminants found withthe housing or electronic enclosure.

Although contaminant control media can be manufactured from a singlesubstance, mixtures of materials are also useful, for example, silicagel can be blended with carbon particles. In some embodiments, thecontaminant control media includes layers or combinations of materials,so that different contaminants are selectively removed as they passthrough or by the different materials.

It will be appreciated that, contaminant control media can undertakemany forms including powdered (passes through 100 mesh), granular(passes through 28 to 200 mesh), beads, slurry, paste and anycombination thereof.

Filter Media

Filter media of the present invention may contain one or moreparticulate filter layers to prevent particulate contaminants fromentering the electronic enclosure from the filter assembly. Suchparticulate contaminants may originate outside of the electronicenclosure or may be shed from the contaminant control media. Filters ofthe present invention may also include particulate filter layers toprevent particulate contaminants from entering the filter assembly fromoutside of the electronic enclosure. They may be disposed on the outsideof the filter assembly or disposed inside of the filter assembly.

The filter media may comprise a variety of porous or microporousmembranes. The size of the pores in the membranes and the thickness ofthe membranes often determine, at least in part, the size of particlesallowed through the membrane and filter.

Often the porous or microporous membranes are formed from polymers.Examples of suitable porous or microporous membranes include porous ormicroporous polyethylene, polypropylene, nylon, polycarbonate,polyester, polyvinyl chloride, polytetrafluoroethylene (PTFE), and otherpolymeric membranes. An especially suitable filtering layer is expandedpolytetrafluoroethylene (ePTFE) because of its good filtrationperformance, conformability to cover adsorbent layers, and cleanliness.A preferred ePTFE membrane has a filtration efficiency of 99.99% at 0.1micrometer diameter sized particles with a resistance to airflow ofapproximately 20 mm water column at an airflow of 10.5 feet per minuteface velocity. ePTFE is commercially available under the registeredtrademark GORE-TEX by W. L. Gore & Associates, Inc.

In one embodiment, the filter assembly is shown with a porous supportlayer disposed within the internal cavity of the filter housing. Thecontaminant control media is disposed on the porous support layer. Forexample, a mesh or scrim can be used as the porous support layer to holdthe contaminant control media. Polyester and other suitable materials(such as polypropylene, polyethylene, nylon and PTFE) can be used as themesh or scrim. The porous support layer can be used as a base on whichthe adsorbent media is disposed.

Typically, any porous support layer is not more than about 40% of theweight of the adsorbent material, and is generally about 10 to 20% ofthe total filter media weight.

Filter Housing

The filter housing may be, for example, an outer covering, a casing, ora shell. The housing is typically formed from a plastic material, suchas, for example, polycarbonate, polyvinyl chloride, nylon, polyethylene,polypropylene, or polyethylene terephthalate. The housing may be asingle piece or, alternatively, the housing may be formed as two or morepieces that are combined together using, for example, an adhesive,mechanical connectors, heat sealing, and ultrasonic welding to form, forexample, a perimeter seal.

It should be noted that in the context of this invention the referenceto the “reduction” or “removal” of contaminants refers to theclarification of a fluid (e.g., gas or liquid) being filtered. The fluidbeing clarified in a hard disk drive enclosure is typically an airstream. It should be appreciated, however, that streams of other gasesor liquids could also be clarified by the filter construction of thepresent invention. The reduction or removal of contaminants from aliquid or gas stream by a filter construction can also be referred to asentrapment, immobilization, adsorption, absorption, neutralization, orotherwise binding (e.g., by covalent, ionic, coordinative, hydrogen, orVan der Waals bonds, or combinations thereof) of the contaminants insideor on the surface of the filter construction.

It should be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the content clearly dictates otherwise. It should also be notedthat the term “or” is generally employed in its sense including “and/or”unless the content clearly dictates otherwise.

All publications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thisinvention pertains. All publications and patent applications are hereinincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated by reference.

This application is intended to cover adaptations or variations of thepresent subject matter. It is to be understood that the abovedescription is intended to be illustrative, and not restrictive. Thescope of the present subject matter should be determined with referenceto the appended claims, along with the full scope of equivalents towhich such claims are entitled.

1. A method for filling a filter assembly with a contaminant controlmedia, the method comprising: a) providing a housing, the housingcomprising: (i) an internal cavity defined by a first surface, a secondsurface and one or more sidewalls connecting the first and secondsurfaces, (ii) at least one fill port in communication with the internalcavity, (iii) at least one breather port in communication with theinternal cavity, wherein the contaminant control media is of sufficientsize, shape, or composition that it is unable to pass through thebreather port, and (iv) a filter media at least partially covering atleast one surface of the housing; b) coupling the housing to a loadingstation at an attachment location, wherein the attachment location formsa seal sufficient to draw a partial vacuum across the filter media, c)sealing the breather port such that a partial vacuum can be generatedwithin the internal cavity, d) providing contaminant control media; e)creating a negative pressure within the internal cavity by drawing apartial vacuum on at least a portion of at least one surface of thehousing at least partially covered by filter media to flow air throughthe fill port; f) drawing the contaminant control media through the fillport into the internal cavity, g) uncoupling the housing from theloading station and loading unit, and h) sealing the fill port afterdrawing the adsorbent material into the internal cavity.
 2. The methodof claim 1, wherein the filter media comprises ePTFE.
 3. The method ofclaim 1, wherein the contaminant control media is an adsorbent materialthat comprises activated carbon, silica gel, or combinations thereof. 4.The method of claim 3, wherein the adsorbent material is selected fromthe group powdered, granular, beads, slurry, paste or combinationsthereof.
 5. The method of claim 1, wherein the contaminant control mediacomprises a neutralization material that comprises an immobilized acid,base, enzyme, or catalyst or combinations thereof.
 6. The method ofclaim 1, wherein the filter assembly is configured for insertion into anelectronic enclosure.